Automatic press brake back gauge

ABSTRACT

A back gauge for a press brake having a stop assembly controlled by an indexing roller. The stop assembly is positioned adjacent a press brake die and punch by a pneumatic cylinder actuated in response to the position of the press brake ram. The indexing roller controls the positioning of the stop member at preselected distances from the press brake die to control the position of a work piece on the press brake die.

waited States Patent [191 Braden [54] AUTOMATIC PRESS BRAKE BACK GAUGE[76] Inventor: Edwin Henry Brauer, 3876 Silsby,

Cleveland, Ohio 44111 22 Filed: Apr. 19, 1971 21 Appl.No.:138,459

[52] U.S. C1 ..72/461, 72/389 [51] Int. Cl. ..B2ld 111/22 [58] Field ofSearch ..72/461, 36, 380, 72/385, 386, 389

[56] References Cited UNITED STATES PATENTS 2,782,831 2/1957 Todd..72/461 784,726 3/1905 Yates ..72/461 11] 3,733,885 51 May 22, 19732,627,890 3/1953 Lloyd ..72/461 3,421,359 1/1969 Gibbs ..72/4613,592,033 7/1971 Murdoch ..72/36 2,618,349 11/1971 Roch ..72/36 PrimaryExaminer-Charles W. Lanham Assistant ExaminerGene P. Crosby Att0rneyAlanN. McCartney [57] ABSTRACT A back gauge for a press brake having a stopassembly controlled by an indexing roller. The stop assembly ispositioned adjacent a press brake die and punch by a pneumatic cylinderactuated in response to the position of the press brake ram. Theindexing roller controls the positioning of the stop member atpreselected distances from the press brake die to control the positionof a work piece on the press brake die.

27 Claims, 21 Drawing Figures PATENT 122 1915 SHEET 1 OF 4 INVENTOREDWIN H. BRAUER 4 2 M (Mir n7 ATTORNEYS PAIENTEL mzz I973 733 5 SHEET 3BF 4 ED H. BRAUER Loafing ATTURNFYS PATENIE mzz 1973 SHEET 0F 4 FIGZOINVENTGR EDWIN H. BRAUER ATTORNEYS NATURE AND OBJECTS OF THE INVENTIONIt is an object of this invention to provide a back gauge for a pressbrake which will automatically position a stop member with respect tothe press brake to control the position of the work piece with respectto the die.

It is a further object of this invention to provide a back gauge for apress brake having a stop member actuated by a pneumatic cylinder andpositioned with respect to the press brake die to control the distance awork piece is inserted over the die.

It is a still further object of this invention to provide a back gaugefor a press brake having a stop member for positioning a work piece onthe press brake die wherein the back gauge is transversely and laterallyadjustable with respect to the press brake.

It is another object of this invention to provide a back gauge for apress brake having an indexing roller controlling the position of a stopmember against which a work piece is placed wherein the indexing rollerautomatically positions the stop member with respect to the press brakedie upon the rise and fall of the ram of the press brake.

It is another object of this invention to provide a back gauge for apress brake having a stop member for positioning a work piece withrespect to the press brake die, the back gauge having an indexing rollerautomatically indexed by a stop member on each stroke of the ram of thepress brake to position the stop member with respect to the press brakedie.

BACKGROUND OF INVENTION In the past, in the use of press brakes forforming articles, a manually positioned stop member has been used tolimit the distance at which a work piece is inserted over a press brakedie. In practice in forming articles having multiple bends, the workpieces resulting in the desired articles would be formed as follows. Thepress brake back gauge would be manually positioned to form one of thebends in a work piece and each work piece individually would then beplaced in the press brake die to form that particular bend. Then, theback gauge would be manually repositioned to form the next bend and eachwork piece would be again separately formed by the press brake. Thisprocedure of forming separate bends in each work piece required eachwork piece to be handled a multiplicity of times during the formingoperation.

To eliminate these multiple handling problems during a press brakeforming operation, it was determined that it would be desirable toperform all forming operations on a given work piece before commencingany forming operations on the next work piece. In essence, performingall forming operations on a given work piece to form the desiredresulting article before performing any additional forming operations onthe next work piece was desirable to eliminate multiple handling of eachwork piece. This required the development of a back gauge which wouldautomatically position a stop member with respect to the press brake diea multiplicity of distances from the die so that each work piece couldbe inserted a variety of distances into the die in order that aplurality of forming operations on a single work piece in sequence couldbe performed. Further, it was determined that such a stop member shouldbe sequentially positioned in response to the rise and fall of the pressbrake ram to be repositioned during each forming operation. It is anautomatically positioned back gauge of this type that forms the new andnovel invention of this disclosure.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a top planview of the back gauge of this invention attached to a press brake.

FIG. 2 is a side sectional view of the press brake taken along lines 2-2of FIG. 1.

FIG. 3 is a fragmentary side elevational view of the press brake backgauge of this invention.

FIG. 4 is a side sectional view of the press brake taken along lines 4-4of FIG. 1.

FIG. 5 is an enlarged sectional view taken along lines 5-5 of FIG. 4.

FIG. 6 is an enlarged sectional view taken along lines 6-6 of FIG. 4.

FIG. 7 is a projection view of the indexing roller with cam roller inpositions of indexing the guide roller.

FIG. 8 is an enlarged fragmentary sectional view taken along lines 8-8of FIG. 4.

FIG. 9 is a fragmentary view of the indexing roller with skip indexingvalve.

FIG. 10 is a sectional view taken along lines 10-10 of FIG. 9.

FIG. 11 is a sectional view taken along lines 11-11 of FIG. 9.

FIG. 12 is an enlarged sectional view taken along lines 12-12 of FIG. 4.

FIG. 13 is an enlarged sectional view taken along lines 13-13 of FIG. 4.

FIG. 14 is an enlarged sectional view taken along lines 14-14 of FIG. 1.1

FIG. 15 is an enlarged sectional view taken along lines 15-15 of FIG. 1.

FIG. 16 is an enlarged sectional view taken along lines 16-16 of FIG. 1.

FIG. 17 is a sectional view taken along the lines 17-17 of FIG. 16.

FIG. 18 is an enlarged sectional view of a modified adjustable stopbutton.

FIG. 19 is an enlarged view of an extension of a stop button.

FIG. 20 is an enlarged view of an adjustable stop plug for the indexingroll.

FIG. 21 is a plan view of the cam actuator and valve on the press brake.

DESCRIPTION OF INVENTION The automatic back gauge of this invention canbe utilized with any conventional press brake or similar type formingapparatus, one of which is diagrammatically illustrated in the drawing.The press brake 1 comprises a press brake bed 2, a bolster 2, a die 2",a punch 3 and ram 3'. In normal operation, through the rise and fall ofthe ram 3' with punch 3 against die 2", a predetermined givenconfiguration of bend can be placed in a work piece 4 which is held overthe die 2" of the press brake. The back gauge assembly 5 of thisinvention has a stop member assembly 6 which can be positioned a varietyof different distances from the die 2" and, thus, the press brake tolimit the distance of insertion of work piece 4 over the die (see FIG.3) to place the work piece at a desired location for forming,

for example, a bend as illustrated in FIG. 4, in the work piece.

The back gauge assembly 5 comprises support brackets 7 which mount theentire assembly on the press brake bed 2. The support brackets 7comprise rails 8 laterally spaced on bed 2 and fixed to the bed on theirupper and lower ends (not shown) by threaded sockets 9 welded at 10 tothe back side 11 of the bed 2. The rails 8 are provided with openings 12in their upper and lower ends, through which lock bolts 13 pass andwhich are threaded into the sockets 9 to hold rails 8 securely on thebed 2. Also, the bolts 13 are provided with washers 14 and lock washers15 to securely affix the rails 8 with respect to the bed 2.

Extending upwardly from the bottom or lower ends (not shown) of eachrail 8 is an angle rail 16. Attached to the upper ends 17 and 18 of therails 8 and 16 respectively, are main support beams 19 and 20. The beams19 and 20 are attached to rails 8 and 16 respectively, as by weldments21. Beams 19 and 20 extend transversely away from the back edge 11 ofbed 2 and are laterally spaced with respect to the bed as illustrated inFIG. 1.

The beams 19 and 20 are identical in cross-section and are illustratedin enlarged detail in FIGS. 16 and 17. Each beam 19 and 20 have T-shapedtroughs 22 having an enlarged portion 23 and a throat portion 24. Eachof the troughs 22 receive two lock nuts 25 each having a head 26 seatedin the enlarged portion 23 and a neck 27 carried in the throat portion24 of the troughs 22. The troughs 22 of the beams 19 and 20 serve toprovide an adjustable support for cross beams 28 and 29 to transverselyposition the cross beams 28 and 29 with respect to the die 2".

The cross beams 28 and 29 are each carried on the upper edge 30 of eachof the main support beams 19 and 20.. The cross beams 28 and 29 (seeFIGS. 16 and 17) also each contain troughs shown at 31, which areidentical in the cross-section. The troughs 31 each comprise an enlargedportion 32 and a throat portion 33. Adjacent each end 34 of the crossbeams 28 and 29 are openings 35 for receipt of lock bolts 36. The bolts36 have heads 37 seated on shoulders 38 in openings 35 and a shankportion 39 threaded into threaded openings 40 in iocknuts 25. Each ofthe bolts 36 contain a hex or slotted opening (not shown) in heads 37for tightening heads 37 of bolts 35 against shoulders 38 of openings 35and securing heads 26 of the lock nuts 25 in enlarged portions 23 oftroughs 22 of the main support beams 19 and 20. To position cross beams28 and 29 with respect to die 2", the machine operator merely inserts atool into the head 37 of each bolt 36 to loosen lock nuts 25.Thereafter, the cross beams 28 and 29 can be each positioned on the mainsupport beams 19 and 20 and thus appropriately spaced from the die 2".Thereafter, the operator merely retightens the bolts 36 to securelyposition the cross beams 28 and 29 on the main support beams 19 and 20.

The troughs 31 each carry at least two lock nuts 41 having heads 42 andnecks 43. The heads 42 are seated in enlarged portions 32 of troughs 31and the necks 43 of lock nuts 41 are carried in throat portions 33 ofthe troughs 31. The arrangement of lock nuts 41 in troughs 31 permitlateral adjustment of a main support plate 44 of the back gauge assembly5, as will become apparent hereinafter.

The main support plate 44 extends between the cross beams 28 and 29 andis carried on the upper surface 45 of each of the cross beams. Adjacentthe ends 46 of the support plate 44, where the support plate overlapsbeams 28 and 29, are provided openings 47 in the support plate. Theopenings 47 receive threaded lock bolts 48 which are threaded into locknuts 41. The bolts 48 have head portions 49 retained on the supportplate 44.

The support plate 44 can be laterally positioned on the rails 28 and 29by loosening bolts 48 and sliding lock nuts 41 in troughs 31 tolaterally locate the support plate with respect to the die 2". Also, thesupport plate can be transversely positioned with respect to the die 2"through the previously described adjustable positioning of cross beams28 and 29 on main support beams 19 and 20. Since the operable oroperating portions of the back gauge assembly 5 are carried on the mainsupport plate 44, the operating portions of the back gauge assembly 5can be both laterally and transversely positioned with respect to thedie 2" of the press brake.

The inner end 50 of support plate 44 carries posts 51 secured to theupper surface 52 of the support plate by weldments 53. The outer end 54of the support plate 44 carries a post plate 55 secured to the uppersurface 52 of the support plate by weldments 56. The posts 51 each haveopenings 57 and the post plate 55 has two openings 58 (see FIG. 14) eachof which are aligned with one of the openings 57 on posts 51. Theopenings 57 and 58 each receive guide rails 59 which are securely lockedinto the openings 57 and 58 by lock screws 60 (see FIG. 14) carried onpost plate 55. The guide rails are positioned above support plate 44 andextend away from the back side of the die 2".

Carried on the guide rails 59 is a guide plate 61 which has elongatedopenings 62 receiving each of the guide rails 59. The openings 62 arelarger than the diameter of rails 59 so that the plate 61 is freelyslidable on the rails 59.

The guide plate 61 is positioned on the guide rails 59 by means of apneumatic cylinder 63. The cylinder 63 comprises the conventionalchamber 64 with a cap plate 65 for receipt of power in bleed lines (notshown). The cylinder 63 is supported on post plate 55. The inner end capplate 66 of cylinder 63 carries a plate 67 which is secured to postplate 55 by means of lock bolts 68.

The cylinder rod 69 of cylinder 63 extends through an opening 70 in postplate 55 (see FIG. 14). The opening 70 is larger than the diameter ofrod 69 permitting the rod 69 to freely pass through the post plate 55.The end 71 of cylinder rod 69 is received in an opening 72 in the rearface 73 of the guide plate 61. A lock screw 74 retains the end 71 of rod69 in the opening 72. With this arrangement, it can be seen thatactuation of the cylinder 63 through the connection of cylinder rod 69with guide plate 61, will cause the guide plate to move toward or awayfrom the die 2" on guide rails 59.

The guide plate 61 on its upper face 75 carries an upwardly extendingsupport plate 76. The support plate 76 is secured to the guide plate 61by means of bolts 77 which pass through openings 78 in the guide plateand are threaded into threaded openings 79 on the under surface 80 ofsupport plate 76 (see FIG. 15). This par ticular type of connection ofthe guide plate to the support plate 76 permits removal of the supportplate from the guide plate to insert different types of support plates.

The support plate 76 has a plurality of elongated openings 81 and 82each of which receive an adjustable stop button 83. The stop buttons 83comprise a bolt 84 having a head 85 and a threaded end 86. The buttons83 pass through openings 81 in plate 76 with the head 85 of the button83 being spaced from the plate 76 by sleeves 87 positioned between thehead 85 and a washer 88 on the plate 76. The bolt 84 carries anotherwasher 89 on the rear side of plate 76 and a lock nut 90 threaded on thebolt 84 to retain the entire stop button assembly on plate 76 in theopenings 81 and 82 on the plate.

The function of the stop button assembly is to be positioned by means ofthe pneumatic cylinder and guide plate connection adjacent the die ofthe press brake to limit the distance of insertion of the work piece 4over the die 2" at the time the punch 3 places the desired bend in thework piece (see FIG. 3). Also, the mounting of the stop button assemblyon the support plate 76 through the slot connections 81 and 82 permitsthe button assembly to be located a variety of vertical distances fromthe surface of die 2" for varyingishapes and configurations of workpieces formed by the press brake.

The back gauge assembly of this invention also provides a means forautomatically controlling the length of stroke of the guide plate thuspositioning of the stop button assembly with respect to the die varyingthe distance of insertion of the work piece over the die.

The underside 91 of the support plate 44 carries brackets 92 and 93. Thebrackets 92 and 93 are carried on the inner end 50 and outer end 54,respectively, of the support plate 44 by weldments 94. The brackets 92and 93 each contain an opening 95 for receipt of bearing pins 96 and 97.The pins 96 and 97 each have heads 98 with radial locking grooves 99cooperating with lock clips 100 carried on the brackets 91 and 92 bybolts 101. The lock clips 100 contain legs 102 which seat in the lockgrooves 99 to retain the pins 96 and 97 in the brackets 92 and 93.Removal of the bolts 101 from brackets 92 and 93 will also permitremoval of the bearing pins 96 and 97 from the brackets to remove theindexing roller 103 carried by the pins 96 and 97 from the brackets forreasons that will become apparent hereinafter.

The bearing pins 96 and 97 carry the indexing roller 103 by means of acentrally located opening 104 extending from end to end of the roller103. The opening 104 at each end of the roller is enlarged for receiptof a bearing cup 105 into which the bearing pins 96 and 97 are received.This arrangement of the indexing roller 103 being mounted on the bearingpins 96 and 97 through bearing cups 105 permits the roller to freelyrotate on the bearing pins.

Positioned between the inner end 106 of the indexing roller 103 and thebracket 92 is a shock absorbing assembly 107 (illustrated in FIGS. 4, 12and 13). The shock absorbing assembly comprises a plate 108 retained onpin 96 by an opening 109 in the plate. The plate 108 has a flangeportion 110 about opening 109 which rests against flange 111 of bearingcup 105. The plate 108 carries a shock plug 112 which has an opening 112through which pin 96 passes. The shock plug 112 is carried on plate 108by means of screws 113 threaded into openings 114 in the plug 112.

The shock plug 112 contains a plurality of recesses 115 into whichsprings 116 are received. As illustrated in FIG. 4, the springs areretained in recesses 115 by plate 108. The recesses 115 have openings117 in their opposite face through which shock pins 118 pass. The pins118 have head portions 119 against which the springs 116 are retained.The pins 118 also have end portions 120 which bear against the bracket92 which forms a reaction point for the springs 116 as will becomeapparent.

Attention is now directed to FIGS. 4, 5, 6 and 7 wherein the details ofthe indexing roller 103 are illustrated. The outer surface 121 of theroller 103 contains a plurality of troughs or grooves122,123,124,125,126,127,128 and 129. Each of the grooves 122 to 129contain an enlarged inner portion 130 and a reduced throat portion 131.The grooves 122 to 129 extend from the inner end of 106 of the roller103 and terminate at 132 at an angular radial recess 133 adjacent theouter end of the roller. Each of the throat portions 131 of the grooves122 to 129 are cut back at the recess 133 to provide a cam surface 134.

Adjacent the recess 133 at the outer end of the roller 103 is provided aradial shoulder 135 having a plurality of cam surfaces 136. The camsurfaces 136 contain an inclined cam face 137 extending from the face138 of the shoulder 135. The cam face 137 commences from face 138 justabove the center line of the grooves 122 to 129 in each instance, asillustrated in FIG. 7. The cam face 137 then extends away from the face138 toward the outer end of the roller to a point of an arcuate bottomcam surface 139. The radius for the arcuate cam surface 139 is taken ona center line beyond the inner section 140 of cam surface 134 with thepoint of termination 132 of the grooves 122 to 129 at recesses 133.

Attention is now directed to FIGS. 1 and 2, 4 and 15 which illustratethe cooperation of the guide plate and stop button assembly with theindexing roller 103. The underside 141 of the guide plate 61 carries camroller support plate 142 (as by weldments 143). The support plate 142passes from the underside of plate 61 through a slotted opening 144 inmain support plate 44 for free back and forth movement with guide plate61. The lower end 145 of support plate 142 contains a leg 146 whichcarries a cam roller 147 and an abutment 147'. The cam roller 147 iscarried by a bolt 148 and, as illustrated, is positioned by plate 142into the grooves 122 to 129. The cam roller 147 rides in the throatportion 131 of the grooves 122 to 129.

The indexing roller 103 also includes a stop plug 149 illustrated inFIG. 8. The stop plug 149 is retained in the grooves 122 to 129 atvarying locations to limit the travel of the roller 147 in the groovesto position the stop button 83 varying distances from the die 2". Thestop plug 149 comprises an abutment bushing 150 retained in the grooves122 to 129 by a bolt 151. The bolt 151 has a head 152 received in theenlarged portion 130 of each of the grooves 122 to 129. The bolt 151also has a threaded end 153 on which is received a lock washer 155 and alock nut 154 to position the bushing in the grooves. The bushing 150 hasa shoulder 156 received in the throat 131 of the grooves 122 to 129 and,as illustrated in FIG. 8., is retained therein by the bolt head 152 inthe enlarged portion 130 of grooves 122 to 129 and the lock nut 154.

Attentionis now directed to FIG. 21 wherein there is diagrammaticallyillustrated a valve and cam member which would be carried by the bed ofthe press brake. The purpose of the valve illustrated at 157 is toactuate the pneumatic cylinder 63. The valve 157 comprises aconventional plunger 158 and roller 1S9 carried on the end 160 of theplunger. The roller cooperates with a cam 161 carried on the bed of thepress brake. The cam 161 will rotate in response to the rise and fall ofthe ram of the press brake to operate the valve 157 to cause operationof the pneumatic cylinder 63. In operation, as will become apparent, thecam 161 causes operation of valve 157 to cause retraction of thecylinder rod 69 when the ram and punch are retracted from the die 2" andupon the ram reaching its upper position causing the cylinder rod tomove the guide plate and thus stop button assembly outwardly to itsouter most position. At this point, the machine operator can place thework piece over the die of the press brake and up against the stopbuttons (see FlG. 3).

In operation, actuation of the pneumatic cylinder 63 through its plungerrod 69 will cause the guide plate to move outwardly on guide rods 69.Through the connec-- tion of support plate 142 with the guide plate 61,the cam roller 147 will ride outwardly in one of the grooves 122 to 129until the abutment 147' on plate 142 strikes a predetermined positionedstop plug 149. At this point, the machine operator will insert the workpiece into the die to abut the stop button 83. Thereafter, the punchwill move downwardly and form the appropriate bend in the work pieceagainst the die. Upon withdrawal of the punch from the die, thepneumatic cylinder 63 will be actuated, as previously described, towithdraw plunger 69 causing the guide plate to move away from the dieand the roller 147 will be retracted down one of the grooves 122 to 129.As the roller 147 moves downone of the grooves 122 to 129, it willcontact the cam face 137 (see FIG. 7). Further withdrawal of the plungerwill cause the cam roller 147 to move down the cam surface 137 causingthe roller (which is freely rotatable on its support pins 96 and 97) torotate causing the roller 147 to move further down cam face 137 to apoint of seating in the arcuate bottom cam surface 139 of shoulder 135of the cam roller 103. At this point, the plunger of the cylinder iscompletely withdrawn and actuation of the cylinder for extension of theplunger will cause the cam to move out of the arcuate bottom cam surface139 of the shoulder 135 to a point wherein it contacts the cam surface134 of one of the grooves 122 to 129. Further extension of the cylinderrod will cause the roller to move down the cam surface 134 causing theindexing cylinder to rotate additionally until the roller contacts thenext one of the grooves 122 to 129 in sequence. This phase of theindexing of the cam roller is illustrated diagrammatically in thevarious positions 1 through in FIG. 7. As the piston rod is furtherextended, the roller will move down the next one in sequence of thegrooves 122 to 129 until abutment 147' strikes another of the stop plugs149. In this fashion, it can be seen that by positioning stop plugs inthe grooves 122 to 129 in various locations, as illustrated, at leasteight different locations of the stop buttons 83 with respect to the die2" can be obtained.

It should also be noted that as the support plate abutment 147' contactsa given stop plug 149, there will be considerable force against the endof cylinder 103. The pins 118 of shock absorbing assembly 107 willcontact the bracket 92 causing absorbtion of such force through springs116 of the shock absorbing assembly to prevent damage to the entireapparatus. Further, the provision of release means for removal of thecylinder 103 from pins 95,96 through lock clips 100 permits the cylinder103 to be preset with the bushings 150 in the tool room, for example,for the next desired forming operation.

Reference is now made to FIGS. 9 to 11 wherein there is illustrated ameans for skip indexing of the indexing roll. That is, in the event, forexample, it is desirable to only make three or four bends in aparticular work piece (less than eight) then provision must be made toskip index certain of the working grooves 122 to 129 of the index roll.This is accomplished by the provision of a bleed valve 162 which, whenoperated, will permit the cylinder 63 and its piston rod 69 to moveoutwardly to permit roller 147 to cooperate with cams 137 and 134 toindex the roller 103 but immediately retract the piston rod toaccomplish a double index on a given rise and fall of the ram and punch.This is accomplished by the provision of a conventional valve member 162being attached, for example, to the bracket 93 by means of bolts 163.The valve would contain an actuating arm 165 attached to the valve 162to operate the valve when pivoted. The arm 165 could contain a camroller 166 on the end thereof. On the outer surface 121 of the indexroller 103 there is provided apertures radially from the roller 166 intowhich screws 167 can be threaded. Upon movement of the index roller 103,the roller 166 can contact the heads 167 causing actuation of the valve162 to cause immediate retraction of the cylinder rod to double indexthe cylinder.

Attention is now directed to FIGS. 18 and 19 wherein modifications ofthe stop buttons 83 are illustrated. In FIG. 8 there is illustrated astop button which would pass through either opening 81 or opening 82 ofthe support plate 86 and be retained therein by bolts 170 and 171 onopposite sides of the support plate. The stop button 168 also comprisesa threaded portion 172 which receives a sleeve 174 retained thereon andpositioned by a lock nut 175. The sleeve 173 has a stop face portion174. It can be seen that the sleeve 173 can be adjusted on the threadedportion 172 of the button 168 varying distances from the support plate76 and thus varying distances from the arbor 2.

FIG. 19 illustrates a still further embodiment of the stop button ofthis invention. In this illustration, a sleeve shown at 176 could becarried by the threaded portion 172 of a stop button of the type 168..This sleeve is also threaded on the stop button 168 and retained thereonby a lock nut 177. The sleeve 176 carries a right angle feeler gauge 178retained on the sleeve by a lock screw 179. This again is a stillfurther embodiment of an adjustable stop button arrangement.

Attention is now directed to FIG. 20 wherein there is illustrated afurther embodiment of an abutment bushing arrangement. In this bushingarrangement, the bushing 180 is retained in the grooves 122 to 129 by apair of lock bolts 181 and 182 which are retained in the grooves in thesame manner as lock bolts 151. This bushing arrangement also has anadjustable stop nut 183 which can be positioned in a threaded opening184 in the bushing and retained therein by a lock screw 185 to give moreaccurate control to the positioning of cam 147 at its outer most stroke.

Other modes of applying the principle of this invention may be employedinstead of those specifically set forth above, changes being made asregards the details herein disclosed provided the elements set forth inany of the following claims, or the equivalent of such be employed.

I claim:

1. A back gauge mechanism for a press brake having a stop memberautomatically positioned in response to the rise and fall of the ram andpunch of the press brake to provide an abutment against which a workpiece placed on the press brake die can be positioned, said back gaugecomprising:

a. apparatus carried adjacent the die of the press brake for supportingthe back gauge;

b. a guide mechanism carried by said apparatus for movement toward andaway from the press brake die;

0. means carried by said apparatus and connected with said guidemechanism actuated in response to the rise and fall of the press brakepunch to cause said guide mechanism to perform said movement;

d. a stop member carried on said guide mechanism and positioned by saidguide mechanism adjacent the press brake die to form an abutment for awork piece inserted over the die;

e. positioning means carried by said apparatus and coacting with saidguide mechanism in response to movement of the guide mechanism toposition said guide mechanism and said stop member varying predetermineddistances from the press brake die to provide a variable abutmentagainst which the work piece can be positioned.

2. The back gauge mechanism of claim 1 wherein said apparatus comprisesmain support beams carried adjacent the press brake and extendingtransversely thereto and cross support beams carried on the main supportbeams laterally to the press brake die.

3. The back gauge mechanism of claim 2 wherein said connection betweenthe main support beams and cross support beams is adjustable to permitthe cross support beams to be positioned toward or away from the pressbrake die.

4. The back gauge mechanism of claim 1 wherein said apparatus comprisesmain support beams positioned transversely to the press brake and crosssupport beams adjustably carried on the main support beams and a mainsupport plate positioned transversely to the press brake die andadjustably carried on the cross support beams for lateral adjustmentwith respect to the press brake die.

5. The back gauge mechanism of claim 1 wherein said apparatus includesmeans for adjustably, laterally and transversely positioning said guidemeans and said positioning means with respect to the press brake die.

6. The back gauge mechanism of claim 1 wherein said means connected withsaid guide mechanism comprises a pneumatic cylinder having a piston rodconnected to said guide mechanism to move said guide mechanism inresponse to the rise and fall of the press brake ram and punch.

7. The back gauge mechanism of claim 1 wherein said guide mechanismcomprises guide rails carried by said apparatus transversely to thepress brake die and a guide plate slidable on said guide rails, the stopmemher being carried on the guide plate.

8. The back gauge mechanism of claim 7 wherein said means carried bysaid apparatus includes a pneumatic cylinder having a piston rodconnected to said guide plate.

9. The back gauge mechanism of claim 7 wherein the guide plate carries acamming mechanism which actuates said positioning means to limitmovement of said guide plate and said stop member toward the press brakedie.

10. The back gauge mechanism of claim 1 wherein said positioning meanscomprises an indexing roller freely rotatably carried on said apparatusand actuated by the movement of said guide mechanism to position theguide mechanism varying distances from the press brake die.

11. The back gauge mechanism of claim 10 wherein said indexing rollercomprises an elongated cylindrical member having a plurality of radialgrooves extending longitudinally of the roller, and abutment means carried in said grooves varying distances longitudinally on said roller tocoact with said guide mechanism to position said guide mechanism withrespect to the press brake die.

12. The back gauge mechanism defined in claim 10 wherein said indexingroller contains cam means and said guide mechanism contains a cam rollercooperating with said cam means to index said roller on each movement ofsaid guide mechanism toward and away from the press brake die.

13. The back gauge mechanism of claim 12 wherein said indexing rollercontains longitudinally extending grooves and camming means coactingwith said grooves and said guide mechanism contains a cam rollercoacting with said grooves and said camming means to index said rolleron each movement of said guide mechanism toward and away from said pressbrake die.

14. In a back gauge assembly for a press brake having a mechanismproviding an abutment against which a work piece is placed, an indexingapparatus to control the position of the mechanism with respect to thepress brake die comprising:

a. a cylindrical member supported for free rotation and having aplurality of radial longitudinally extending grooves adapted to coactwith the abutment mechanism;

b. said grooves terminating adjacent one end of said cylindrical memberin a radial recess and providing a first camming surface;

c. and a shoulder on said one end of said cylindrical member providing asecond camming surface;

d. said first and said second camming surfaces being adapted to coactwith the abutment mechanism to rotate said cylindrical member andposition the abutment mechanism with respect to the press brake die.

15. The back gauge assembly of claim 14 wherein the first cammingsurface comprises a shoulder on the end portion of each of said groovesintersecting said radial recess and said second camming surfacecomprises recesses in said cylindrical member shoulder radially offsetfrom said first camming surface.

16. The back gauge assembly of claim 15 wherein the second cammingsurface includes an arcuate bottom cam surface having a radius drawn ona center line beyond the intersection of said first camming surface withsaid radial recess.

17. A back gauge assembly for a press brake having a punch and die, saidback gauge comprising:

a. apparatus for supporting said back gauge adjacent the press brakedie;

b. abutment means supported on said apparatus for free movement towardand away from the press brake die;

0. means for moving said abutment means toward and away from the pressbrake die;

d. control means carried by said apparatus actuated by the abutmentmeans during said movement toward and away from the press brake die;

e. said control means including means limiting the movement of saidabutment means toward said die to preselected distances from the die toprovide a variably positioned abutment adjacent the press brake dieagainst which a work piece is placed.

18. A back gauge assembly of the type defined in claim 17 wherein saidabutment means includes means coacting with said control means to causeactuation of the control means for limiting said movement of saidabutment means.

19. A back gauge assembly of the type defined in press brake die.

21. A back gauge assembly of the type defined in claim 20 wherein saidmounting of said roller includes a shock absorbing assembly to absorbthe longitudinal load on the indexing roller upon said stops limitingmovement of said abutment means.

22. A back gauge assembly of the type defined in claim 21 wherein saidshock absorbing assembly is carried on said indexing roller mounting andreacts against said apparatus to absorb longitudinally directed loads onsaid roller.

23. A back gauge assembly of the type defined in claim 17 wherein saidabutment means includes guide rails carried on said apparatus transverseto the press brake and a guide plate freely slidable on said guide railsfor movement toward and away from the press brake.

24. A back gauge assembly of the type defined in claim 23 wherein theguide plate carries stop buttons against which a work piece is placed.

25. A back gauge assembly of the type defined in claim 24 wherein thestop buttons are vertically adjustable on the guide plate.

26. A back gauge assembly of the type defined in claim 25 wherein thestop buttons are horizontally adjustable on the guide plate.

27. The back gauge mechanism of claim 13 wherein said indexing rollerincludes valve actuating means and a valve mechanism controlled by saidvalve actuating mechanism to control said means carried by saidapparatus to skip index said indexing roller.

1. A back gauge mechanism for a press brake having a stop member automatically positioned in response to the rise and fall of the ram and punch of the press brake to provide an abutment against which a work piece placed on the press brake die can be positioned, said back gauge comprising: a. apparatus carried adjacent the die of the press brake for supporting the back gauge; b. a guide mechanism carried by said apparatus for movement toward and away from the press brake die; c. means carried by said apparatus and connected with said guide mechanism actuated in response to the rise and fall of the press brake punch to cause said guide mechanism to perform said movement; d. a stop member carried on said guide mechanism and positioned by said guide mechanism adjacent the press brake die to form an abutment for a work piece inserted over the die; e. positioning means carried by said apparatus and coacting with said guide mechanism in response to movement of the guide mechanism to position said guide mechanism and said stop member varying predetermined distances from the press brake die to provide a variable abutment against which the work piece can be positioned.
 2. The back gauge mechanism of claim 1 wherein said apparatus comprises main support beams carried adjacent the press brake and extending transversely thereto and cross support beams carried on the main support beams laterally to the press brake die.
 3. The back gauge mechanism of claim 2 wherein said connection between the main support beams and cross support beams is adjustable to permit the cross support beams to be positioned toward or away from the press brake die.
 4. The back gauge mechanism of claim 1 wherein said apparatus comprises main support beams positioned transversely to the press brake and cross support beams adjustably carried on the main support beams and a main support plate positioned transversely to the press brake die and adjustably carried on the cross support beams for lateral adjustment with respect to the press brake die.
 5. The back gauge mechanism of claim 1 wherein said apparatus includes means for adjustably, laterally and transversely positioning said guide means and said positioning means with respect to the press brake die.
 6. The back gauge mechanism of claim 1 wherein said means connected with said guide mechanism comprises a pneumatic cylinder having a piston rod connected to said guide mechanism to move said guide mechanism in response to the rise and fall of the press brake ram and punch.
 7. The back gauge mechanism of claim 1 wherein said guide mechanism comprises guide rails carried by said apparatus transversely to the press brake die and a guide plate slidable on said guide rails, the stop member being carried on the guide plate.
 8. The back gauge mechanism of claim 7 wherein said means carried by said apparatus includes a pneumatic cylinder having a piston rod connected to said guide plate.
 9. The back gauge mechanism of claim 7 wherein the guide plate carries a camming mechanism which actuates said positioning means to limit movement of said guide plate and said stop member toward the press brake die.
 10. The back gauge mechanism of claim 1 wherein said positioning means comprises an indexing roller freely rotatably carried on said apparatus and actuated by the movement of said guide mechanism to position the guide mechanism varying distances from the press brake die.
 11. The back gauge mechanism of claim 10 wherein said indexing roller comprises an elongated cylindrical member having a plurality of radial grooves extending longitudinally of the roller, and abutment means carried in said grooves vaRying distances longitudinally on said roller to coact with said guide mechanism to position said guide mechanism with respect to the press brake die.
 12. The back gauge mechanism defined in claim 10 wherein said indexing roller contains cam means and said guide mechanism contains a cam roller cooperating with said cam means to index said roller on each movement of said guide mechanism toward and away from the press brake die.
 13. The back gauge mechanism of claim 12 wherein said indexing roller contains longitudinally extending grooves and camming means coacting with said grooves and said guide mechanism contains a cam roller coacting with said grooves and said camming means to index said roller on each movement of said guide mechanism toward and away from said press brake die.
 14. In a back gauge assembly for a press brake having a mechanism providing an abutment against which a work piece is placed, an indexing apparatus to control the position of the mechanism with respect to the press brake die comprising: a. a cylindrical member supported for free rotation and having a plurality of radial longitudinally extending grooves adapted to coact with the abutment mechanism; b. said grooves terminating adjacent one end of said cylindrical member in a radial recess and providing a first camming surface; c. and a shoulder on said one end of said cylindrical member providing a second camming surface; d. said first and said second camming surfaces being adapted to coact with the abutment mechanism to rotate said cylindrical member and position the abutment mechanism with respect to the press brake die.
 15. The back gauge assembly of claim 14 wherein the first camming surface comprises a shoulder on the end portion of each of said grooves intersecting said radial recess and said second camming surface comprises recesses in said cylindrical member shoulder radially offset from said first camming surface.
 16. The back gauge assembly of claim 15 wherein the second camming surface includes an arcuate bottom cam surface having a radius drawn on a center line beyond the intersection of said first camming surface with said radial recess.
 17. A back gauge assembly for a press brake having a punch and die, said back gauge comprising: a. apparatus for supporting said back gauge adjacent the press brake die; b. abutment means supported on said apparatus for free movement toward and away from the press brake die; c. means for moving said abutment means toward and away from the press brake die; d. control means carried by said apparatus actuated by the abutment means during said movement toward and away from the press brake die; e. said control means including means limiting the movement of said abutment means toward said die to preselected distances from the die to provide a variably positioned abutment adjacent the press brake die against which a work piece is placed.
 18. A back gauge assembly of the type defined in claim 17 wherein said abutment means includes means coacting with said control means to cause actuation of the control means for limiting said movement of said abutment means.
 19. A back gauge assembly of the type defined in claim 18 wherein said control means comprises an indexing roller mounted on said apparatus for rotational movement and said roller having radial longitudinally extending grooves coacting with said abutment means during said movement toward and away from the press brake die.
 20. A back gauge assembly of the type defined in claim 19 wherein stops are positioned at varying distances along the longitudinally extending grooves to limit the movement of said abutment means toward the press brake die.
 21. A back gauge assembly of the type defined in claim 20 wherein said mounting of said roller includes a shock absorbing assembly to absorb the longitudinal load on the indexing roller upon said stops limiting movement of said abutment means.
 22. A back gauge assembly of the type defined in claIm 21 wherein said shock absorbing assembly is carried on said indexing roller mounting and reacts against said apparatus to absorb longitudinally directed loads on said roller.
 23. A back gauge assembly of the type defined in claim 17 wherein said abutment means includes guide rails carried on said apparatus transverse to the press brake and a guide plate freely slidable on said guide rails for movement toward and away from the press brake.
 24. A back gauge assembly of the type defined in claim 23 wherein the guide plate carries stop buttons against which a work piece is placed.
 25. A back gauge assembly of the type defined in claim 24 wherein the stop buttons are vertically adjustable on the guide plate.
 26. A back gauge assembly of the type defined in claim 25 wherein the stop buttons are horizontally adjustable on the guide plate.
 27. The back gauge mechanism of claim 13 wherein said indexing roller includes valve actuating means and a valve mechanism controlled by said valve actuating mechanism to control said means carried by said apparatus to skip index said indexing roller. 